In traditional consist arrangements, the cooling systems and power controls of each locomotive may be controlled separately. In such arrangements, there is no information exchange, communications link, or control coordination among the locomotives' cooling systems or power controls. As a result, each locomotive's control system is required to derate its respective engine when the engine coolant temperature exceeds the allowable maximum of that particular locomotive and its cooling system is operating at full capacity. However, the cooling air inlet temperatures of each locomotive in the consist are interrelated, especially in tunnel conditions.
When a consist passes through a tunnel, each locomotive transfers heat from the engine to the surrounding ambient air, which is then trapped inside the tunnel until the consist passes through. As a result, a trailing locomotive's cooling system receives air that has been increasingly heated by each locomotive preceding it into the tunnel. This may cause engine coolant temperatures to be increased above permissible limits, requiring power derating of the trailing locomotives. In prior art systems, derating is performed on each locomotive based solely on its own environmental and engine conditions. This power control reduction occurs without reference to or consideration of the power levels of the other locomotives in the consist. As a result, the total train power of the consist may be lower than necessary, especially for locomotive operation in tunnel conditions.
One solution for maintaining locomotive operation in tunnel conditions is described in U.S. Pat. No. 7,072,747 B2 (“the '747 patent”). The '747 patent is directed to a method of controlling passage of a consist through a tunnel that purportedly maintains a sufficient combined performance capability from the locomotives to move the consist through the tunnel.
The solution provided by the '747 patent requires that the locomotives are each configured, prior to the consist entering the tunnel, for passage through the tunnel. This requires advanced configuration of the consist based on the tractive effort required to move the consist through the tunnel and the relative location of each locomotive within the consist. Additionally, this requires anticipation of the characteristics of each tunnel the consist will pass through. The solution provided by the '747 patent is unable to operate unless it receives location data related to both the tunnel and the relative location of each locomotive in the consist. Once the consist is traveling through the tunnel, the method disclosed in the '747 patent purportedly is able to dynamically change which of the locomotives is idling to maintain a sufficient total train effort. However, the method of the '747 patent is unable to control the cooling systems of each of the locomotives, nor does it disclose dynamic derating of the locomotives. Rather, the disclosed control is limited to switching the mode of a locomotive between idling and full tractive power.
The presently disclosed power control system is directed to overcoming one or more of the problems set forth above and/or other problems in the art.